GSI Uncovers Undisclosed Lab-Grown Diamonds in Brown Diamond Jewellery

Gemological Science International (GSI) has identified undisclosed lab-grown diamonds (LGDs) within jewellery pieces featuring natural brown diamonds. The revelation comes amid rising demand for off-colour natural diamonds—especially brown and champagne hues—celebrated for their uniqueness, affordability, and fashion appeal.

Employing sophisticated detection techniques such as Fourier Transform Infrared Spectroscopy (FTIR), DiamondView imaging, and Raman spectroscopy with liquid nitrogen cooling, GSI gemmologists verified that several tested jewellery items contained a combination of natural and lab-grown stones. The analysed diamonds varied from nearly colourless with faint brown tones to deep, fancy brown shades.

This latest discovery reinforces GSI’s earlier research on coloured lab-grown diamonds, which highlighted how synthetics can closely imitate natural colour variations. The institute emphasized the importance of stringent screening processes and transparent disclosure to uphold industry credibility and consumer confidence.

“As natural brown diamonds continue to gain traction, protecting their authenticity is crucial,” stated Debbie Azar, President and Co-Founder of GSI. “Through advanced science and detection, GSI remains committed to safeguarding the trade, empowering retailers and manufacturers, and ensuring that natural off-colour diamonds are promoted with integrity and transparency.”